Material not showing when above me

straight to the point: I’m trying to create a stream, coming down from a hill. When i’m at the top, the stream appears perfectly as it should, but when i’m standing under the mountain, its texture (material) is invisible. I need to point out it’s the same side of the mesh, so not a “two sided” checkbox fault. Basically, above my head on Z axis, the water material is invisible. Can you please help me, why could this be?
The material in question:
It is a problem with the material, it disappears even on the preview orb when looking at it from below.

Thanks a lot, Betaraptor01

Ok solved, i had to remove the “Camera position and substract” nodes.